La Unión is a municipality located in the Zacapa department of Guatemala, situated in the eastern region of the country. As an administrative division within Zacapa, it serves as a local governance center for its surrounding communities and rural areas.
The municipality is part of Zacapa's broader geography, which is characterized by mountainous terrain and significant agricultural activity. Like other municipalities in the region, La Unión functions as a municipal seat with typical administrative responsibilities for local governance and public services in its jurisdiction.